1. Field of the Invention
The present invention relates to J-shaped hooks for carrying a load, and more particularly to a J-shaped hook for use in towing a vehicle, the hook being designed and configured to provide greatly improved strength at a light weight to withstand loading conditions associated with such Use.
2. Description of the Prior Art
J-shaped hooks, commonly referred to as "J-hooks" are well known in various applications for connecting a load to a chain or the like. J-hooks are typically used for towing vehicles, such as by coupling an eye of the J-hook to a tow chain of a recovery vehicle and connecting an arcuate portion of the J-hook to a fixed member of the vehicle to be towed or to a chain attached to such a fixed member.
Many J-hooks, such as those described in U.S. Pat. Nos. 1,459,816 and 2,646,306, are designed exclusively for generally constant vertical loading conditions associated with suspension of a load. J-hooks designed for vertical suspension loading are generally ill-suited for use in vehicle towing due to their short "reach", defined as the distance from an inner radius of an arcuate portion of the J-hook to the center of an attachment opening in an eye portion at an opposite end of the J-hook.
Common prior art J-hooks designed for the purpose of towing Vehicles have been produced by bending a suitable length of steel rod of a given diameter into the desired J shape, forming an eye portion with an attachment opening at a top end of the J, and tapering the tip of the J. J-hooks of this type have been manufactured using 7/8" diameter bar stock and have a yield strength of approximately 7,000 pounds.
U.S. Pat. No. 4,171,842 issued Oct. 23, 1979 to Tolle discloses a J-hook for towing vehicles which has a thickened elbow section to enhance the strength characteristics of the J-hook. Tests conducted by applicant indicate that the J-hook of Tolle has a minimum breaking strength, defined as the load or force at which the J-hook fails or no longer supports the load under standard testing conditions, of less than 10,000 pounds.
Prior art J-hooks for towing vehicles, including the Tolle J-hook and J-hooks of the bent steel rod variety, have a tendency to slip off of a connection member of the load vehicle or a chain attached thereto when there is slack in the tow chain, for instance when the load vehicle is being prepared for towing.